Electric motor.



No. 718,518. PATENTED JAN. 13, 1903;

E. S. PILLSBURY.

ELECTRIC MOTOR.

APPLICATION FILED JULY 24, 1902. y no MODEL. 3 SHEETS-SHEET 1.

PATENTED JAN. 13, 1903.

E. S. PILLSBURY.

ELECTRIC MOTOR.

APPLICATION PI-LED JULY 24, 1902.

3 SHEIBTSSHEET 2.

H0 MODEL.

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No. 718,518. PATENTED JAN. 13, 1903. B. S. PILLSBURY. ELECTRIC MOTOR. APPLICATION FILED JULY 24, 1902, -no MODEL. 3 SHEETSSHEET.8.

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EDWVIN S. PILLSBURY, OF ST. LOUIS, MISSOURI.

ELECTRIC MOTOR.

PECIFICATION forming part of Letters Patent No. 718,518, dated January 13, 1903.

Application filed July 24, 1902. Serial No. 116,852. (No model.)

To a whom zit may concern.-

Be it known that I, EDWIN S. PILLSBURY, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Electric Motors, of which the following is a full, clear, and ex act description, such as will enable others skilled in the artto which it appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a vertical longitudinal sectional view through my improved electric motor. Fig. 2 is a cross-sectional View on line 2 2, Fig.1. Fig. 3 is an end elevational view with part of the casing broken away. Fig. 4 is a top plan View of the forward end of the machine, a part of the casing being partly broken away to more clearly show the interior. Fig. 5 is a cross'sectional view on line 5 5, Fig. 1. Fig. 6 is an enlarged detail view of a brushholder; and Fig. 7 is a plan view, partly broken away, of the forward end of the armature-shaft.

This invention relates to a new and useful improvement in electric motors, being designed particularly as an improvement upon the construction shown in United States Letters Patent No. 620,609, granted to myself and Ferdinand Schwedtmann on March 7, 1899.

The type of motor shown in the accompanying drawings is designed to be run by alternating currents and is self-starting. The brushes are electrically connected at all times, and when the speed of the motor is built up a centrifugal device, practically in the form of a governor, is operated to short-circuit the commutator, the brushes being removed from said commutator, so that at normal or high speed the motor runs as an induction-motor.

My present invention consists in the details of construction, arrangement, and combination of the several parts, all will hereinafter be described and afterward pointed out in the claims.

In the drawings, 1 indicates a casing,which is substantialiy cylindrical in cross-section, being provided with bosses 2 at its ends and in the interior of the casing for receiving bolts by which the heads 3 are secured in position. These heads are formed with bearings 4 for the armature-shaft.

5indicates an overhanging flange extending inwardly from the casing for supporting the field-core 6, which, as usual, is composed of laminations. This flange 5 is trued up in practice, after which the field-core is built up thereon, leaving a space 7 therebetween and the casing, and when the core is complete a ring 8 is introduced into position, and some suitable binding material 9, which can be poured into the space between the parts and then solidify, is introduced between said ring ands-aid field-core and serves to hold the same firmly in place. Many binding materials can be employed; but in practice I employ sulfur and type-metal, the sulfur extending from the flange across the field-core and the type-metal extending from the sulfur to the outer edge of the ring 8. Ring 8 is formed with an outwardly-extending flange, which becomes embedded in the binding material and prevents the displacement of the ring, while a shoulder l0 is formed in the casing for the purpose of preventing the binding material and the field-core from becoming displaced.

As the interior of the casing is contracted by the presence of the lugs 22, some means must be provided for introducing the laminations of the field-core into the casing, and this I accomplish by providing an opening or slot 11 in the casing of a Width slightly exceeding the diameter of a lamination of the field-core. This slot preferably opens through the bottom of the casing, and in building up the field-core in the casing the laminations are introduced therethrough and deposited on the flange 5 until the field-core is of the required dimensions, when the ring 8 is placed in position and the Babbitt metal or other binding material poured, as before described.

12 indicates the armature shaft, which finds bearings in the hubs 4. This armatureshaft is formed with a shoulder 18, against which a flange-ring 14 abuts, said flange-ring serving as a spider-plate for the armature laminations 15.

16 indicates the rear spider-plate for clamping the armature laminations on the shaft, said ring being pressed home by means of a nut 17, threaded onto the armature-shaft. This clamping-ring or spider-plate 16 affords a convenient support for the centrifugal device which is employed when the motor has attained a speed to automatically relieve the tension upon the brushes and short-circuit the commutator.

lsindicates posts mounted upon the spiderplate 16, which posts afford supports for plates 19, which are slotted, as at 20, to have a variable fulcrum on the posts. Plates 19 are provided with swivel-lugs 21 on their inner faces, which are connected by links 22 to the outer ends of bell-crank levers 23, said bell-crank levers being pivotally mounted in lugs extending from plate 16. The other members of these bell-crank levers are formed with sockets for cooperating with rods 24, said rods extending through the armaturecore and cooperating with a sliding ring 25, mounted on the opposite side of the armature. (See Figs. 1 and'7.) The plates 19 lie and move in planes transverse the longitudinal axis of the shaft and are at the side of the armature, while the rods 24 extend across the armature and have movement in planes parallel with the longitudinal axis of the shaft. Thus ample space is afforded for the necessary movement of the plates, and at the same time the armature extends only the usual distance about the shaft.

The ring 25 is held inwardly by means of an interiorly arranged spring 26, bearing against the inner end of said ring, the outer end of said spring being seated against a ring or spring seat 27, which is slidingly mounted on the armature-shaft. This ring 27 is provided with interior screw-threads for receiving and holding in position a block 28, said block having its ends threaded to cooperate with the ring and being mounted in slots 29 in the armature-shaft. A centrally-arranged screw-plug 30, introduced through a threaded opening in the forward end of the armatureshaft, bears against this block, and by adjusting this plug the block may be moved inwardly, so as to place the spring under greater compression. The purpose of this construction, therefore, is to adjust the yielding, resistance to the movement of the ring 25 in order to properly time the throw'of said ring dependent upon the speed of the armatureshaft, which speed sets into motion the centrifugal devices before described.

Ring 25 at its rear end is formed with con verging flanges 31, between which are introduced short-circuiting plates 32. These shortcircuiting plates are preferably stamped out and are introduced into position between the flaring flanges through an opening at one point in the periphery thereof, after which the plates are slid around into position, and in this waya solid concentric series of plates is formed. When the series is completed, a drop of solder or other means may be employed to hold the plates in position. These plates 32 are not held tightly in position between the converging flanges, but are permitted a limited outward movement under centrifugal force, so that any wear of the plates will be taken up, and the plates directly engage the commutator-segments when the ring 25 is in its advanced position. The plates are preferably recessed in their inner edges to cooperate with a guiding-rib on the ring 25 between the converging flanges. The plates are also recessed in their outer faces, so as to permit their forward ends to rest on the commutator-segments over the edge of the ring 36.

The commutator consists of plates 33, properly insulated from each other, said plates being held in position by a shouldered engagement with an insulation-ring 34, which is clamped by suitable screws to a flanged ring 35. This flanged ring has a screwthreaded engagement with the spider-plate 14 of the armature, as shown in Fig. 1.

36 indicates an insulated ring of conducting material whose inner periphery is flush with the inner edges of the concentric series of the commutator-plates, said ring being clamped into position by the commutatorsegments and so located as to hold the shortcircuiting plates 32 in position when the motor is at rest and to electrically connect said plates when the motor has attained a speed and when the plates have been moved into position to engage the com mutator-segments.

' 37 indicates a brush-support, preferably mounted by a screw-threaded connection upon the inner end of the hub 4 of the front head-plate of the casing. This brush-support is provided with suitable housings 38, extending radially therefrom, in which are slidingly mounted brushes 39. These brushes are held inwardly against the commutatorsegments by means, preferably, of a spiral leaf-spring 40, mounted on posts extending from the brush-support. On the side of each brush-housing 38 are links 41, which are pivoted at their outer ends to said brush-housing and at their inner ends to a connector 42. This connector is provided with an inwardlyextending projection 43, operating through an opening in the brush-support, and said connector is also provided with an extension 44, which is in the path of the free end of its associate spring 40, whereby when said connector is moved outwardly (by the ring 25) the extension 44 will engage and lift the spring 40 from the brush, and thus relieve said brush of tension. This, however, only happens when the armature has attained a high speed.

The brush-support, as will be observed, is in the form of a short cylinder open at its inner end, said cylinder supporting a slidable ring 45, preferably made in two parts secured together, so as to provide an internal annular groove for receiving a flange 46 on the outer end of ring 25. This groove is somewhat wider than flange 46, so as to permit the ring 25 to rotate freely therein and also to allow a slight lost motion of the outward movement of the ring before engaging and moving the ring 45.

In the drawings I have not shown any of the electrical connections nor the manner of winding and wiring my improved motor, as the same is well understood, being substantially that illustrated in Patent No. 620,609, hereinbefore referred to. The operation of the mechanical elements above described is extremely simple. In the normal position of the parts such as shown in Fig. 1, the brushes bear against thecommutatorand the short-circuit-ing plates 32 are out of electrical contact with the commutator-segments and in engagement with the insulation ring 36. When the current is turned on the motor and speed attained, the centrifugal devices are thrown into action, sliding the ring 25 forwardly on the arn'iature-shaft, so as to place the plates 32 into contact with the com m utator-segments, short-circuiting them and subsequently through the medium of the parallel-movement links relieving the brushes of tension, so that they are out of contact with thecommutator-segments. The partsremain in this position as long as the motor maintains its high speed, and, as described in the patent before referred to, under such conditions the motor runs as an induction-motor.

I am aware that many minor changes in the construction, arrangement, and combination of the several parts of my device can be made and substituted for those herein shown and described without in the least departing from the nature and principle of my invention.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a motor, the combination with a commutator, of brushes therefor, a short circuit ing device cooperating with said commutator and normally out of contact therewith, a centrifugal device for moving said short-circuiting device into position to engage the commutator -segments, springs for holding the brushes in contact with the commutator-segments, and means operated by said centrifugal device for engaging the springs and relieving the brushes of tension; substantially as described.

2. In a motor, the combination with a commutator, of a shortcircuiting device cooperating therewith and out of contact with the same when the motor is starting, brushes which cooperate with the commutator when the motor is started, springs for forcing said brushes into contact with the commutatorsegments, and means actuated when the motor has attained a speed for throwing the short-circuitingdevice into position to engage the commutator-segments, said means also engaging and lifting the springs from the commutator-segments; substantially as described.

3. In a motor or the like, a commutator, a

supporting member, and short circuiting plates which are mounted upon said member to move bodily radially toward said commutator, there being a tongue-and-groove connection between said plates and said supporting member; substantially as described.

at. In a motor or the like, a commutator, a supporting member, short-circuiting plates which are mounted thereon to move bodily radially toward said commutator, and means integral with said supporting member for preventing twisting of said plates; substantially as described.

5. In a motor or the like, a commutator, a rotatable supporting member provided with a peripheral groove having overhanging Walls, and short-circuiting plates loosely mounted in said groove and confined therein by said walls; substantially as described.

6. A casing for motors and the like comprising a body portion having interior bosses at its end, a head upon said end, and securing members for said head seated in said bosses, said casing being provided with a slot for the insertion of laminations; substantially as described.

7. A casing for motors and thelike provided with a slot for the insertion of laminations; substantially as described.

8. A casing for motors and the like having a slot in its under side forthe insertion of laminations; substantially as described.

9. In a motor or the like, a shaft, a commutator, a movable short-circuiting device cooperating therewith, centrifugally-operated plates connected to said shaft and movable in planes transverse the longitudinal axis thereof, and connection between said plates and said short-circuiting device; substantially as described.

10. In a motor or the like, a shaft, an armature thereon, a commutator upon one side of said armature, a short-circuiting device cooperating with said commutator and movable along the longitudinal axis of said shaft, centrifugally-operated plates connected to said shaft upon the otherside of said armature and movable in planes transverse the longitudinal axis of said shaft, members extending across said armature and connected to said short-circuiting device, said members moving in a plane substantially parallel with the longitudinal axis of said shaft, and operative connection between said plates and said members; substantially as described.

11. In amotor or the like, a commutator, a movable short-circuiting device cooperating therewith, a shaft, plates pivotally connected to said shaft and extending in a plane transverse the same, longitudinally-movable operating parts connected to said short-circuiting device, and means whereby said parts are moved by the action of said plates; substantially as described.

12. In a motor or the likc, a commutator, a movable short-circuiting device cooperating therewith, a shaft, a plate thereon, posts extending from said plate, plates provided with elongated openings receiving said posts, whereby said plates are pivotally mounted and extend in a plane transverse said shaft, rods having operative engagement with said short-circuiting device and movable in planes parallel with said shaft, and operative connection between said rods and said pivotal plates; substantially as described.

13. Inamotororthelike,asupportingmemher having a flange, commutator-segments adjacent said supporting member and having parts engaging said flange and the body portion of said supporting member, a clampingring in the angle between said flange and the body portion of said supporting member and clamping said segments, and a fastening member engaging said ring and said supporting member; substantially as described.

14:. In a motor or the like, a commutator, a movable short-circuiting device cooperating therewith, yielding means tending to move said device in one direction, means for moving said device in opposition to the force of said yielding means, and means accessible from the exterior of the apparatus for adj usting the said yielding means; substantially as described.

15. In a motor or the like, a commutator, a movable short-circuiting device cooperating therewith, a slotted supporting member, a spring-seat slidable thereon, a spring between said seat and said short-circuiting device, a block movable in said slot and connected to said seat, and means for moving said block; substantially as described.

16. In a motor or the like, a commutator, a movable short-circniting device cooperating therewith, a shaft having a transverse slot, a spring-seat upon said shaft,a block connected to said seat and movable in said slot, means for adjusting said block, and a spring between said seat and said short-circuiting device; substantially as described.

17. In a motor or the like, a commutator, a movable short-circuiting device cooperating therewith, a shaft having a transverse slot and a longitudinal opening communicating with said slot, an interiorly-threaded sleeve upon said shaft, a spring intermediate said sleeve and said short-circuiting device, a block in said slot and having threaded ends engaging the threads of said sleeve, and a plug adjustably seated in said longitudinal opening and engaging said block for adj usting the same; substantially as described.

18. In a motor or the like, a commutator, brushes cooperating therewith, a brush-support, tension members carried by said brushsupport and acting upon said brushes to hold them in engagement with the commutator, parts movably supported upon said brush support and movable against said tension members to relieve pressure upon said brushes, and means for moving said parts; substantially as described.

19. In a motor or the like, a commutator, a cylindrical support, brushes upon said support, tension members acting upon said brushes to hold them against said commutator, a ring in said support, means whereby movement of said ring causes said tension members to be moved from said brushes, and means for moving said ring; substantially as described.

20. In a motor or the like, a commutator, brushes cooperating therewith, a cylindrical brush-support, tension members acting upon said brushes to hold them against the commutator, a movable ring in said brush-support, means whereby the movement of said ring causes movement of said tension members, short-circuiting plates'cooperating with said commutator, a movable support therefor, operative connection between said shortcircuiting-plates support and said ring, and means for moving said short-circuiting-plates support; substantially as described.

21. In a motor or the like, a commutator, brushes cooperating therewith, a cylindrical brush-support, tension members acting upon said brushes to hold them against the commutator, a grooved ring movable in said brush-support, means whereby movement of said ring causes movement of said tension members, a second movable ring suitably supported, a flange upon said ring loosely seated in said groove, short-circuiting plates upon said second ring, and means for moving said second ring; substantially as described.

22. In a motor or the like, a casing, a shaft, a co1nmutator,a cylindrical support upon said casing and extending about said shaft, brushes upon said support, tension members acting upon said brushes to hold them against said commutator, a grooved ring movably supported in said cylindrical support, said support being slotted, members extending through said slots and serving to effect operative connection between said ring and said tension members, a short-circuiting-plates supporting-ring mounted upon said shaft. short-circuiting plates carried thereby and cooperating with said commutator, a flange upon said latter-mentioned ring loosely entering the groove in said first-mentioned ring, and means for moving said plates-supporting ring; substantially as described.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 22d day of July, 1902.

EDWIN s. PILLSBURY.

Witnesses:

GALEs P. MOORE, GEORGE BAKEWELL. 

